The current state of the art of harvesting methods for root crops do not adequately provide for the removal of clods of soil from the crop while at the same time protecting the quality of the crop. Indeed, in order to provide an adequately cleaned root crop, hand labor is presently being used to remove the clods at some point downstream of the harvesting equipment.
There have been several attempts at providing equipment to mechanically reduce the size of the soil clods so that the clods can be removed. One prior method involves simply passing the mixture over a slotted or linked conveyor chain; the smaller soil clods falling through the chain while the root crop, such as potatoes, being retained on top of the conveyor chain. In practice, this approach has proved not to be effective, and has led to such improvement attempts as jiggling the conveyor chain to try to break up the clods, passing the clod/root crop mixture over rubber rollers with eccentric elements or paddles and/or tumbling of the clods/crop mixture in other various mechanical devices. It has been found that these methods not only do not break up the soil clods sufficiently to allow their separation, but also can severely damage the root crop by bruising.
It is a generally accepted fact that handling root crops along with relatively large amounts of soil tends to protect the root crop from bruising. In effect, the soil provides a cushion for the potatoes or the like during the harvesting and subsequent handling processes. We have discovered that soil clods when mixed with the potatoes can be effectively broken into reduced size with less pressure than is required to bruise the potatoes. With this discovery, we have conceived the method and apparatus to handle the root crop, such as potatoes with relatively large amounts of soil in such a way as to not only reduce and eliminate clods but also protect the root crop. A desirable end result is that separation of the reduced size clods can be easily effected downstream, either immediately or in a later handling step.
As a result of our discovery and inventive approach, several advantages can be realized. Generally, higher conveyor speeds, and thus increased harvester speeds are possible because the root crop is protected against bruising by the cushioning of the soil clods. As a result, greater quantities can be harvested by the farmer and handled in a continuous fashion from the point of digging to storing of the crop. The need for hand labor can be substantially eliminated. The farmer can potentially receive a better return on his crop investment, due to not only the time saving in harvesting, but due to the higher quality product produced.